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Begin by examining the data set. Recognize how the data is recorded and how you may be able to use the given data to explore potential relationships between categories.


Scatterplot Questions

1. Create a scatterplot using average MPG and another category that you feel may influence fuel efficiency. Answer the following questions.

  • Identify the category you chose and why you thought there might be a relationship BEFORE creating the scatterplot?

Answer: We chose MPG vs. HP because it usually takes more fuel, smaller MPG, to produce more horsepower.
  • Create the scatterplot. Which category is your x-axis and which is your y-axis? Why did you create your scatterplot in that order?

Answer: The x axis is MPG and the y was horsepower. Because we set MPG as the independent variable and we wanted to look at how the horsepwer changed according to that MPG.
  • Do you believe there is a relationship between the two categories? Why or why not?

Answer: Yes, because as the horsepower decreases the mpg increases at an increasing rate.
  • If there appears to be a relationship, does it have a positive or negative slope? What does this mean about the relationship between the two categories?

Answer: there is a negative slope in the change in horsepower over the change in mpg.

Regression Questions

(What is Regression?)

Create the linear regession equation in Excel, which Excel calls the trend line. Click the boxes to create both the equation and the r2 value on the graph. Answer the following questions.

  • What is your regression equation? Explain what the equation means in words.

Answer: y = -6.362x + 307.5 It means that the horsepower decreases 6.362 for every mile per hour increase.
  • What is your r2 value? Is this a strong correlation? Why or Why not? If you are not sure, try searching the internet for supporting documents. Provide URL's for where you find your information

Answer: .4301 This is not a strong correlation. The scatterplot is not linear.
  • Based on all the information you have, has your belief about the relationship of the two categories changes? Why or why not?

Answer: Yes, we still think that the more horsepower a car has the poorer mpg it will have.


Analysis

Right click on the regression equation and select "Format Trendline". Explore the different variations of regression equations.

  • How would you determine which equation had the best relationship?

Answer: We checked different kinds of regressions to find a better model.
  • Was the "Linear" option the optimal option? If so, why? If not, what was the better equation and why?

Answer: No. We think that a power regression is better because it has a better R squared value



Attach your Scatter Plots and Regression Information. Make sure your X and Y axis are correctly labeled. You may use Screen Shots to do so.